Projectile



June 19, 1923.

L. A. DU NAJEFF PROJECTILE 2 Sheets-Sheet 1 Filed May 2, 1921 A @Ti m 2g June 19, 1923. 1,459,198

1.. A. DUNAJEFF PROJECTILE Filed May 2, 1921 2 Sheets-Sheet 2 INVENTOR leanl cl A. fianajefl 8) 844 ATTORNEY Patented June 19, 1923.

Application filed May 2,

To all whom it may concern:

Be it known that I, LEONID A. DiJNAJEFF, citizen of Russia, and resident of New York, in the county of New York and State of New York, have invented certain 'new and useful Improvements in Projectiles, of which the following is a specification.

My invention relates to projectiles and has forits object to provide a projectile. especially suitable for firing at a very long range.

For firing at a long range ahigh initial velocity is required in order to store in the projectile a suflicient amount of energy to overcome the air resistance. Highinitial velocity necessitates a very long gun, a slow burning powder and a high initial pressure.

' These factors greatly increase stresses in the gun,'its burning, erosion and general deterioration, and shorten considerably the life of such a high powered gun.

In order to increase the firing range without, increasing 7 the initial velocity of the projectile, I am providing a special projectile for high angle firing, of such a form, that my projectile, upon reaching the highest point in its flight, glides downwards at a small angle with the horizon, being supported partly by the vacuum in the air above, partly bythe air pressure underneath, in a manner somewhat similar to the gliding of an airplane.- For this purpose I provide my projectile with specially shaped upper and lower surfaces, also with a protective device adapted to prevent these special surfaces to act until the projectile begins to descend.

- My invention is more fully described in the accompanying specification and drawing in which-- Fig. 1 is an elevation of my projectile partly in section, Fig. 2 isa section through AA, Fig. 3 is a front view of the projectile, Fig. 4 is a sectional view of a locking mechanism for the protective casing, Fig. 5 is a diagrammatic view of a trajectory of flight of my projectile as compared with a trajectory of an ordinary projectile, Fig. 6 is a diagrammatic view of my projectile in flight, showing distribution of forces and the lines of vacuum, Fig. 7 is a sectional elevation of a modified, arrangement, and, Fig.8 is a rear view of same, Figs. 9, 10, 11 and 12 are diagrammatic views of the projectile in flight.

My projectile consistsof a body or shell UNITE Sr? 5 LEONID A. DUNAJEFF, or NEW YORK, 1v. Y.

PROJEC'IILE.

1921. Serial No. 466,034.

The cylindrical portion of my shell is shaped differently on its sides. One side,

which is an upper side in flight, is machined ofl eccentrically, forming a straight shoulder 8. The machining is done by simply placing the shell on a lathe e'ccentrically or off centers and taking a straight cylindrical out,

ric.

until it reaches approximately across. thejdi v ameter, thereby forming a recess 4:.

The lower portion is provide-d with longitudinal grooves 5 forming lateral shoulder-s 6. These shoulders extend from the rear of the shell to the front, terminating on the ogive or pointed portion. are arranged symmetrically on both sides of the plane passing vertically through the longitudinal axis of the shell. The purpose of these shoulders is to provide gliding surfaces for the shell. The forwardportions of these surfaces 8 are raised so as to form a proper angle'9 of incidence with the direc-- tion of flight, indicated by thearrow 10. The

rear portions of the surfaces 6 are inclined to the axis of the shell so asto be almost parallel to the direction of flight 10 of the 1 projectile.

The inclined forward surfaces 8 tend'to raise the front portion of the projectile n flight, so that its axis will form a small angle 11 with the direction of flight 10. The air" under the forward portion will be compressed in proportion to the square of the" velocity of the projectile, producing a lifting force and tending to raise the pro 'ect1le These shoulders higher in the air against its weight. t the same time the recess 4 and the shoulder 3 will produce a vacuum above and behind the projectile also tendingto raise same in the air. The approximate distribution of the vacuum is indicated by the dotted line. 12.

The dotted line 13 indicates the distribution produced by the pressure and the'vacuum,

supports the projectile in the air at a certain angle with the line of flight, this angledepending also on. the velocity of flight. With the center of pressure behind the center of gravity a stable condition of flight will be produced, the projectile maintainingits angular gliding position and travelling at a practically constant speed.' Such condition would have been diflicult to accomplish without a provision for a vacuum lift.

In adjusting itself to'a certain angle the projectile will turn more or less'around its center of gravity 15, so thatthe change from the front curved surfacess to the rear m clined shoulders 6 should be near the Vertical plane containing this center of gravity.

The rear shoulders act only as stabilizers,

' ofl'eringbut a little resis'tanceto the air and being almost parallel to" the normal line of flight. But if the projectile turns and its front portion rises in the air, then the angle of incidence of the rear portion becomes greater, and ts moment arm bemg longer' than that ofthe front portion, it can easily overcomethefront lifting force, thereby re turning the projectile to itsn'ormal'angle of until 'the projectile rightsiitself.

In this respect my projectile acts very" flight. If the angle of incidence becomes .smaller, or theprojectile turnsdownwards,

then thevacuu'm decreases, the lifting force alsojd m' nishes, and the rear portion, sinks similarly to an ordlna'ry airplane, gliding down at a' constantangle and with a constunt glid ng-speed, An ordinary pro ectile,

' after reaching. the highest point of flight,

' tance, depending on 'the height or the apexnil decrease'ofthe velocityfa s' caused by the air friction. About 30 to 40 degrees elevation produces i'lsnally the longest range. The line 16 Fig. 5 indicates the'trajectory of an I ordinary projectile. I

With my proj ectilethe trajectory, after its highestpoint, becomes an almost straight line 17, fdrmi'ng a small anglew'ith the earth, and; although the velocity will be compara-I'. tively low, the projectile, nevertheless, will" glide at a constant speed a Very long dis 1 8 of the trajectory. Itis possible to make the; total gliding distance eight times the height of the trajectory, for instance.

,. than compensated in :my projectile by the enormously increase'df ftotal range of, the

trajectory. On the other hand, .a smooth boremeans much longer 'life'for the gun.

[The symmetrical arrangement of the glid-v .ing. shoulders; and their inclination to the central vertical plane provides means to maintain-the vertical balance of the pro jeqtile and "topr'eve'nt its rotation in flight.

Assn additional security any such begins descend with increasing velocity, a thefs'econd half ofits trajectory is even shorter than} the first-one'on account ofthe rotation a gyroscope may be employed. It represents a gyroscopic Wheel 19 on a shaft 20 mount'eain bearings 21. f

i The bearing block's'may'slide in slots 22 in the-sides of the shell under action of springs 22'. The ;friction between the wheel and the bore will set the Wheel in a rapid rotation which will be maintained during I The gyroscopic force of the Wheel will'prevent any axial rotationof the the flight.

projectile. V

Themqst of the lifting force is produced bythe vacuum recess 4 which, although small, is very-effective'on account o'f the high speed of the projectile. .Itsi action,

however, is not'desirable until the projectile beginsto descend, so that I provide my pro-f jectilewith a protective shell or cartridge 23.

t is made of a thin metal sheet and is forced undersli-ghtpressure over the cylindrical portion of theproje'ctile. The rear 'end of the prote'ctive casing is closed with a heavy bottom plate 24. A copper band 25 rnay be fitted in thefedgein order to seal the shell in the gun and prevent the leakage ofgases during their expansion.

"When the projectileis still insideofthe gun',the pressure oftheexpahding gases will i keep the protective casing pressed tightly against the projectile. 'During thelflightthe air will be forced under pressure through the grooves .5 inside ot'the casing 23 andmay easilythrow it off. In order to prew' ent this I provide a relief valve lforfthe air. a It cone sists of a heavy block 26 "sliding in a recess 27 formed partly in the projectile, partly in the back wall. of the protective casing.

spring 28 tends to move the block back away from' the bottom offthe recess" in the projectile and, to press it against the bottom of the recess in the back plate 5 24. The block 26 is drilled through, and

the "holes '29 are in a connnunication with grooves 30 in the bottom of the projectile, when "the bloclrJis pressedforward against the spring 28.

32. A spring 33forces the valve away from its ,seat 34:, thereby opening the space 31. The holes 35jestablish a communication between the air outside and inside 10f the The pressure otthe gases in the gun, acting through the holes 35, will force the block 26 forward, but, at the same time,-will c lose thevalve. 32, thereby preventing the gases from escaping through the holes 29 and grooves '30. :But after the projectile leaves; the gun, the light spring 33 will force the ishinga eommuni;

valve open thereby estab cation between the air inside of the protec-- tive casing 23 andthe outside and relieving I the "pressure inside, so'thatthe' protective ,casing will stay on the projectile in flight.

The air "friction will cause a deceleration of v p 7 p n The holes '29 passinto ahole 31 in the block containing a valve 26-will keep it the projectile, so that the inertia of the block pressed against'the tension of the spring 28.

During the ascent of the projectile the-air will flowcontinuouslythrough the channels 5, grooves 30 and holes 29, 31 and 35 to the I rear of the shell, coming out in a stream and partly filling the-vacuum behind, forming an elastic streamline extension to the pro jectile, 'thereby' 'reducing materially its resistance'in flight.

"WVhen the projectile reaches the highest pointof flight andbegins to 'descend,' its" closing the passages for the compressed air inside of the protective casing. The accumulated compressed air will force the protective casingofi the projectile, exposing the vacuum recess 4 and the grooves 6. From that moment on the projectile will glide down at a constant speed and at a constant angle, its trajectory being practically straight. line 17.

Fig. 9 represents my projectile in a normal flight during the descent with the center of pressure 14 on the line with the center of gravity 15 and with the forces balanced. The front inclined planes are represented diagrammatically with a line 8. The air pressure on these surfaces produces a vertical lifting component force 36. Distribution of the lifting forces due to the air pressure is marked with dotted lines 44, the vacuum forces are marked in the lines 43. The

rear planes are represented diagrammati- The turning moment produced by the force 36 around the center of gravity will be balanced by the opposite turning moment produced by the force 37 around the same center of gravity 14. Therefore in this position the projectile will tend to conserve its longitudinal position in relation to the line of flight 10, or the angle 11.

Fig. 10 shows distribution of forces when the projectile accidentally turns upwards. In this case the angle of the planes 8 will be increased and consequently-the force 36 will increase also. But to balance this increase the vacuum force 37 will also increase and larger than that of the force 36, there will be'a strong unbalanced turning moment tending to lift the rear :portion, of the pro-v jectile and to restore its normal flying posi- Fig. 11 represents an opposite case,'whe n' the projectile turns downwards. 1n this case the force 36 'will'be decreased onac;- cou'nt of a decrease'of the angle of the 'front plane 8. -'To balance this decrease, however,

the vacuum force 37 -'will be also greatly-dc creased andfits component'shifted' to the front ofthe "shell, shortening the moment arm, the force 38, will reverse its'directi'onq andwill act downwards. The resultant turning noment will tend to lower therear end of the projectile until it takes "its normal flying position, Y

Fig. 12 represents a case whenthe prc- I jectile turns sidewise' in flight. In this case the right surfaces or planes 6 will form large angles 39 with the vertical lifting forces 40, while the corresponding planes 6 on the other 'side'vvill be more nearly at right angles to the vertical components 42. As a result the forces 42'will be greater than the forces 40, so that. the left sidev of the shell will be lifted until the forces become balanced, which will take place with the I symmetrical position of the planes 6 and 6'. around the vertical line.

, My projectile will not function properly unless it is fired in a correct position in regard to its vertical axis, so that the cartridge and the shell itself should have some marks 45 or other provision for correct loading.

Important advantages of my projectile are, T

that it can be used for firing at a very long distance with ordinary amount of powder charge and with ordinary sizes and calibers of the guns, also that with my projectile the expensive and difficult rifiing of the guns can be dispensed with. The initial velocity not being necessarily high, the projectile can be made, comparatively light with a large charge of aneffective explosive, compressed gas or an incendiary material.

I claim as my invention 1. In a projectile, the combination with a shell, a shoulder on the upper side of said shell near its forward portion, and a longitudinally extending recess back of said shoulder. 1

2. In a projectile, means to form a vacuum above said projectile in flight, and means to prevent formation of said vacuum until the projectile reaches .the predeter-- said shell, a protective, casing covering said recess, and means to release saidprotective casin from said projectile at .a predeter? mine 1 5. In a projectile, the'eombination with a point of flight.

shell,.gliding surfaces on the lower side of said shell, vacuum-forming recess on the upper side of said shell, a-protective device ada'pted tocover said vacuum formingrerj ces's, air passages between saidfshell and said protective device, and an inertia-[operated air valve in the rear of said .projectile,'a'dapted to close said passages at the. predetermined point of flight. a

6'. In a projectile, a protective casing-for said projectile, means to admit the air under compression in flight inside of said protective casing, arvalv'eadapted to release said compressedair back of said projectile, and

7. In aprojeetile, a gyroscopic wheel, the

axis ofsaid wheel being perpendicular to the axis ofsaid projectile, and a spring adapted to press said wheel against the bore of the gun. e 1

,8. In a projectile, thecombination with a shell, a transverse shoulder and la recess on the upper "side of said'shell, and a gyroscospic wheel in said shell. ignedat New York, inthe county of New York-and State of New York, this fifteenth April, A. D. 1921.

. (15) dayof i v LEONI D A. DUNAJEFF.

inertia operated means tocontrol said valve. 

